


Cold Feet

by RavenGrey



Category: Big Hero 6 (2014)
Genre: Frotting, Guilt, Hand Jobs, Hiro hits puberty and can't keep his hand out of his pants, Inappropriate brother boners, Kissing, M/M, Masturbation, Plot What Plot/Porn Without Plot, Sibling Incest, Sibling Love, Straddling, Underage Sex
Language: English
Status: Completed
Published: 2015-04-28
Updated: 2015-04-28
Packaged: 2018-03-26 03:52:06
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,713
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3835981
Author URL: https://archiveofourown.org/users/RavenGrey/pseuds/RavenGrey
Summary: <blockquote class="userstuff">
              <p>“Just get over here. This way I won’t have to listen to your teeth chatter all night.” Tadashi’s almost afraid his cheeks are going to spontaneously combust like Baymax did the other day but they don’t and then Hiro’s climbing into his bed.</p>
            </blockquote>





	Cold Feet

**Author's Note:**

> i'm gross. that is all.

            “Again? Really?” Tadashi groans in disbelief, voice muffled by the pillow he’s currently trying to smother himself with. He hears Hiro’s blankets rustle and tries to ignore the burning in his face when Hiro’s head pokes out.

            Hiro’s cheeks are flushed and his hair is messier than usual. Tadashi would be impressed by the way Hiro’s hair is defying gravity if he weren’t still stuck on the fact that he’s almost 100 percent sure that his little brother is in the middle of touching himself for what must be, that he knows of, the 4th time today.

             And of those 4 times, he’d been there for approximately all of them. All. Of. Them.

             It had started, innocently enough, when he’d come back to their room for his hat after breakfast. He didn’t wear it at the table out of respect for Aunt Cass and had forgotten to knock. It had continued when he’d burst in on Hiro in the shower, late for school and needing to brush his teeth.

            His teeth didn’t get brushed and there had been screaming. Lots of screaming.

             One of the most awkward days of Tadashi’s life had ended when Hiro had accidentally (he’s still not sure how that one happened) started a video feed while he taking care of his new, perfectly normal hormonal urges while sitting in Tadashi’s computer chair. Wearing Tadashi’s cardigan from the day before that he’d left on the floor.

            Tadashi had a _very_ interesting day at school after that. Nothing quite says ‘advanced robotics’ like having to hide your very confused boner with your jacket for the rest of the day.

             He was a terrible, awful man and he should be put away, but just the thought of Hiro in _his_ chair with his small, calloused hand wrapped tight around himself is enough to have Tadashi’s heart pounding in his chest and heat pooling low in his belly.

             He feels a little sick with himself, but his guilt doesn’t do much to stop his body reacting when Hiro’s breathy, quiet sounds reach him from across the room as he stops doing what he was doing.

            “I’m pubescent and you’re being really insensitive about my needs during this crucial time in my development and I just do not appreciate that.” Hiro huffs in a pretty good impression of Aunt Cass, even though his voice is shaky and thin.

             Tadashi scrubs an embarrassed hand down his face when Hiro’s raspy voice sends a shiver of heat down his spine.

             “It’s the 4th time _today,_ how are you not exhausted?” Tadashi huffs, wishing he’d remembered to push the further divider out. He gives his lower parts a look of utter betrayal when a sharp throb of arousal punches him in the gut. He pulls his blankets up to his chin. Because he’s cold. Definitely because he’s cold and not because he’s trying to hide his _highly_ inappropriate and _incredibly_ gross boner.

            “You think I’m enjoying this? I’m tired and I just want to sleep, but nooo, my thing has other ideas.” Hiro sounds absolutely furious and really embarrassed.

            Tadashi wishes he hadn’t mentioned it in between trying to muffle his soft laughter with his pillow and trying to smother himself so he doesn’t have to deal with this much awkwardness.

             Tadashi remembers his own ‘blossoming into man hood’, as Aunt Cass had called it, and wishes he didn’t. Puberty was rough on everyone and Tadashi had not been spared its petty wrath. His sudden need for alone time hadn’t really fooled Aunt Cass and he still remembers her ‘loving yourself isn’t a crime’ speech, word for cringe-worthy word.

            The speech itself had been great for his awkward, gangly 13 year old self but her phrasing could have used a _little_ work. Just remembering it makes the back of his neck prickle embarrassment.

            “Are you _laughing_ at my pain you heartless butt-hole?” Hiro whisper-yells, flipping his blankets down and sitting up so his glower has more effect.

             Hiro pushes his damp bangs out of his eyes and reaches down to grab a sneaker by the worn tongue. His aim is true and he flops back down with a satisfied, albeit petty, smile as it arches beautifully though the air.

             Tadashi yelps and cringes in, more startled than anything when Hiro’s sneaker comes flying across the room and gets him in the stomach. 

            “I’m sorry- It’s just-” He breathes outs a quiet laugh and drops the battered shoe by his bed, rubbing at the sore spot “your, your thing?”

            “Yes my thing.” Hiro says hotly, turning his back to Tadashi pointedly and glaring at one of his bot posters.

            “Sorry, sorry, I don’t mean to mock you in this, your gravest hour, but you do know that _your thing_ actually has a name?” Tadashi asks carefully, fighting down his rising mortification as he tries to spare Hiro from the horrors of Aunt Cass’s talk and his delicate sensibilities at the same time.

            He drops his hands down from where they were clenched under his chin and smoothes his blankets. There’s still a smidgen of arousal somewhere in his gross body and he’s really glad Hiro’s far, far away and his gut is still stinging from the shoe bomb.

            Hiro rolls over slowly and gives him an incredibly dry and pitying look for a 14 year old. “No, Tadashi. I did not know that. This is news to me despite the fact that I’ve had access to the internet since I was 2.”

            “Shush, sass-master, or I’ll leave you to the tender mercies of Aunt Cass and her puberty talk _during this crucial time in your development_.” Tadashi mimics Hiro mimicking Aunt Cass.

             He throws his hand up for good measure and Hiro snickers from across the room. Tadashi can barely make out his face in the mess of his blankets and his heart does a weird little pitter-patter in his chest that it definitely shouldn’t be doing as he turns on his side.

            He _really_ wishes he had pulled the room divider back out because a sleepy, indignant, aroused Hiro isn’t something he knows how to deal with even if he’s mostly covered in blankets.

            “You wouldn’t, you’re too nice.” Hiro says, wriggling around and trying to get comfortable. He kicks off his blankets with a miserable groan and peels his sticky shirt away from his skin. It’s borderline freezing but he’s covered in a thin sheen of sweat and his face feels like it’s on fire. He’s also still really hard and the soft, sleep husky timbre of Tadashi’s voice is really not helping.

            In fact it’s doing the opposite of helping and Hiro sucks in a quick breath at the sharp jolt of heat that makes him ache in that new, confusing and inconvenient as heck kind of way.

            “Wanna try me? First thing ‘morrow morning I’m gonna let her know that I’ve failed you as a brother and you need her expertise and wisdom on this delicate matter and then I’m gonna watch you crash and _burn_. ”

            “That’s just evil.” Hiro says, impressed despite the threat of his impending doom. He can practically feel the waves of passive-aggressiveness radiating from Tadashi and he wriggles with annoyance.

            “Thank you.”

            “You’re welcome” Hiro huffs, kicking his feet a little and snuggling deeper into his blankets. San Fransokyo winters are harsh and the attic is _freezing_. He’s got 3 blankets and one of Tadashi’s old nerd school sweaters but he’s still cold now that his prior activities have been put on hold.

            He tosses again, hyper aware of the warm, rapidly cooling wet spot on the inside of his boxers. It’s just on his boxers though, hasn’t bled through to his sleep pants and he briefly considers slinking off into the bathroom just so he can sleep with his shame instead of lying awake with it.

            “Just get over here. This way I won’t have to listen to your teeth chatter all night.” Tadashi’s almost afraid his cheeks are going to spontaneously combust like Baymax did the other day but they don’t and then Hiro’s climbing into his bed. With his cold feet.

            He hisses quietly through his teeth and arches away from Hiro’s cold toes. Hiro grins and jams his feet against Tadashi’s ankles, wriggling them deeper and giving him no quarter as he leeches his leg warmth. It reminds of when he was little and Tadashi would let him cuddle close, even in the summer heat.

             It helps calm down his heart, which is thumping like crazy, and lets him settle more soundly against Tadashi’s solid frame. He’s nervous, like, really nervous even though isn’t even close to the first time he’s spent the night in Tadashi’s bed.

             Okay, so that came out wrong, but he’s tired and Tadashi is _really cute_ when he’s sleepy and he figures he should get a pass on this one. And maybe also the next one. And possibly the one after that? Because he’s hormonal, yep, he’s hormonal and he should definitely be forgiven his bodily transgressions.

            That’s what he’s gonna say if Tadashi suddenly comes to his senses and tells him to get back to his own bed. Which he will. Because Hiro’s hard against Tadashi’s warm, firm thigh and his arm is a very real, reassuring weight across Hiro’s back and oh God what was he thinking this was a bad idea.

             Worst idea. Tadashi’s never going to speak to him again and everything is going to be weirder than it was after the 3rd time Tadashi caught him and that’s _really_ weird.

             At this rate he’s going to have to move to the underground, become a mole-person and make bots out of stray bits of leaves and twigs. It’ll be great.

            “When was the last time you clipped your toe-nails?” Tadashi gripes while kicking at Hiro’s feet in an attempt to keep his scratchy toe-nails away from his ankles. Hiro startles out of his banishment to the kingdom of moles and concentrates on the quiet, soothing rasp of Tadashi’s voice.

            “Neveeer.” Hiro hisses, scrunching his toes and throwing a leg over Tadashi’s. He recoils a bit when his groin rubs against the muscle of Tadashi’s thigh and his heart thumps hard in his chest.

            Tadashi’s ears are burning at the insistent press of Hiro’s arousal. He’s already accepted how icky he is when he’d invited Hiro into his bed knowing full well his predicament. Tadashi almost gives in to the urge to roll off the bed and then maybe under it to express how disappointed he is with himself.

            But he’s always been there for Hiro, good and bad, and he’s not going to let a few awkward conversations and even more awkward boners stop that. Not ever. He throws an arm over Hiro, pulls him close and kisses his temple. He makes a disgusted sound and Tadashi kisses him again, making a loud smacking sound when he pulls away.

            “Gross dude.” Hiro says, even though some of the tension leaks out of him. Not enough for Tadashi’s peace of mind, but a little.

            His arm tightens around Hiro’s back and he traces nonsense symbols over the tight line of Hiro’s shoulders. It takes a minute, but eventually Hiro goes boneless against him, like Mochi when you find that spot just above his butt.

            Tadashi hums, a very neutral sound, and he can almost feel Hiro roll his eyes.

            “I’ll do it in the morning.” Hiro lies, wondering how they’d gone from inappropriate brother boners to his unclipped toe-nails, but Tadashi knows him and just shakes his head in disbelief. Hiro tilts his head back and grins up at him. There’s the faint shadow of stubble on Tadashi’s face and his feathery black hair is sticking straight up.

            Hiro feels almost dizzy with how much he loves his big brother in that moment and it shows when his fingers linger in Tadashi’s hair when he reaches up to smooth it down. 

             “I’ll do it tomorrow, you little gremlin.” Tadashi sighs blissfully, an absolute sucker for having his hair played with, and kisses the top of Hiro’s head.

             “Can you do me now?” Hiro says, burying his face in Tadashi’s chest to smother his laugher. Tadashi makes a horrified sound that vaguely resembles a chuckle.

            “You’re making this really hard on me.” Tadashi groans and Hiro’s head pops up, mouth open and eyes alight with devious hellfire.

            “No. Nope No. Absolutely not. ” Tadashi mashes his hand against Hiro’s face. “Don’t, you horrible little boy.”

            The warm, wet drag of Hiro’s tongue over his palm is nothing new and he just gives him a bland look. “You gonna be gross?” He asks seriously even though he could give a tomato a run for its money.

            Hiro looks rebellious for a second but then shakes his head no. Tadashi drops his hand and wipes it on the sheet absently. Hiro looks even more flustered up close. His pupils are huge and his cheeks are flushed a deep shade of pink. His thin lips look bitten raw and Tadashi runs his thumb over Hiro’s bottom lip.

Hiro huffs out a hot breath against his thumb and wriggles his hips pointedly. “I can-” his voice cracks quietly and looks more embarrassed than Tadashi’s ever seen him “can take care of it if this too weird.”  

            “It isn’t.” He’s not sure where he pulls the low, soothing tone from, maybe his butt? it works though and Hiro looks up at him from under his short lashes. “Really.”

            Tadashi’s hand is warm and gentle when slides it down Hiro’s chest. Hiro shudders against him and makes a breathy, needy sound that Tadashi’s never hear him make before when he brushes his finger softly over the tent in Hiro’s sleep pants.

            Hiro buries his hands in Tadashi’s shirt, hands fisted tightly as sharp zings of pleasure twist in his belly and make him groan in shock.

            “You okay?” His voice is husky and he barely recognizes it. Hiro twitches against his hand and Tadashi’s head swims with the heady feeling of having Hiro here with him, like this.

            “I’m not gonna be if you don’t get the lead out.” Hiro grits through his teeth, grinding his hips against Tadashi’s palm. He’s not sure why Dashi’s hand feels so much better than his, he’s barely even touching him and already that confusing heat is coiling in his hips.

            Tadashi’s hand is big, easily covering Hiro’s throbbing length and then some. Hiro doesn’t ever want it to stop, even though the light pressure of Tadashi’s hand is driving him crazy. He wiggles impatiently even though Tadashi still has him held snug against his chest.

            Tadashi chuckles into his hair and presses a chaste kiss to the top of his head. He starts slow, stroking Hiro lightly through the thin cotton of his pants and letting Hiro get used to the feeling of his hand on him. He’s also giving Hiro time to decide he doesn’t want this, he acknowledges with a guilty twinge.

            He shifts until he’s on his side, so they’re facing each other instead of Tadashi being on his back and puts their foreheads together. Hiro’s short breaths puff against Tadashi’s mouth and he lightly bumps his lips against Hiro’s.

             “Impatient brat.” He murmurs fondly, eye to eye with Hiro. He’s flushed and panting and clinging to Tadashi so tightly that he’s pretty sure his sleep shirt ripped a little. To be fair, it was on its last legs anyway.

             “Geezer.” Hiro puffs back, his lips tingling. Hiro’s been electrocuted before and the feeling running down his spine is close to that. Admittedly with less spasming on the floor.

            Tadashi just grins sweetly and thumbs Hiro’s tip, watches intently when Hiro’s mouth goes slack with pleasure. Hiro’s trust in him makes his heart flutter in his chest and he kisses Hiro’s eyebrow, then his cheek, and finally covers Hiro’s mouth with his own in a full kiss.

            Hiro goes stiff, entire body straining up against Tadashi’s mouth, and actually whimpers when Tadashi’s tongue drags lazily over his bottom lip.

            It’s when he bites down, not hard enough to hurt, and grinds the heel of his palm against Hiro’s straining cock that Hiro comes with a keening moan that’s barely muffled against Tadashi’s eager mouth. Hiro keeps up a steady stream of sounds, hips bucking against Tadashi’s hand as he rides out his orgasm.

            Tadashi strokes him through it, lightening his touches when Hiro starts to wind down and stopping altogether when Hiro is pressed flush against his side, shaking with aftershocks.

            He goes back to rubbing circles on Hiro’s back and lets him catch his breath before he asks teasingly “Better?”

            Hiro smiles up at him, cheeks flushed and tweaks his nipple.

            “Ow!” Tadashi yelps, even though he’s smiling too because Hiro’s sleepy laugh is one of the best things he’s ever heard. “Jerk.”

            Hiro just smirks at him and Tadashi tweaks his nose. “Wanna go get cleaned up?”

            Hiro looks like he’s about to spring out of bed and make a break for the bathroom but he hesitates “What about you?”

            Hiro feels a brief flicker of satisfaction knowing that Tadashi is cherry red because of him, but it gets beaten out by a flare of nervousness.

            “You don’t have to Hiro, not ever if you don’t want to.” Tadashi replies immediately, cradling Hiro’s burning cheek in his calloused palm.

            Hiro’s response is so quiet that Tadashi almost misses it.

            “… I want to.”

            He has to suck in a steadying breath at that, because his dick is definitely on board even though his mind is telling him no. His heart is doing something weird, somersaults maybe? so he ignores it.

            “If-” he has to stop and clear his throat before he can continue “if you want to.” He finishes uncertainly, not realizing that his heart is in his eyes.

            “I do.” Hiro replies bluntly and mashes their lips together. It’s sloppy, but they both get the point and then Hiro is in his lap and he’s just so deliriously happy he has a hard time remembering why his little brother straddling him is a bad thing.

            “You’re awful and I’m gross.” Tadashi groans. “I am a sick, sick man and I should be locked away forever.” He adds pitifully and Hiro grins down at him with his gap tooth smile and his warm, devious eyes and Tadashi knows, without a doubt, that he’s so screwed.   

            Hiro grinds against him, curiously, and smirks at him when he groans quietly. Hiro sucks in a quiet breath at how sensitive he is, how weird the come on his skin feels as he rocks carefully down onto Tadashi’s lap. He can feel the outline of him against the inside of his thigh and wonders if he looks as ridiculous as he feels.

             He’s so much bigger than Hiro, so much more experienced, but Tadashi’s eyes flutter closed and Hiro admires the pretty pink flush on Tadashi’s cheeks. He leans down and presses a brief kiss to Tadashi’s cheek, breath hitching at the sweet press of Tadashi’s hips against his own. He’d say he’s surprised by the fact that he’s hard again, but he’d be lying.

             Tadashi looks at him with such wonder and adoration that Hiro grows more confident and covers Tadashi’s wide, warm lips with his own and kisses him curiously. Tadashi’s lips are soft and caring and Hiro flicks his tongue over the seam of Tadashi’s mouth.

            Tadashi groans, eyes slitting open, and nudges Hiro’s tongue with his own. It’s a gentle brush, but Hiro’s hips jerk hard and he gasps sharply. He’s embarrassed by how wet he is, but it makes the slow grind of his hips against Tadashi’s that much better.

            When they pull apart Hiro’s chest is heaving and Tadashi’s lips are shiny with spit. Hiro leans in and nips his bottom lip, tugging experimentally before sitting back up and really putting his full weight into the next rock of his hips.

            Tadashi fists his hands in the sheet above his head and he buries his face in the crook of his arm. He sinks his teeth into the muscle of his arm to muffle the needy sounds that want to spill past his teeth and tries not too hard about how good Hiro feels against him.

              It’s Hiro’s small hand gripping him through the cotton of his boxers that tips him over the edge. Hiro’s clever fingers moving determinedly over his hard length and the way his eyebrows are knit in concentration as he grips Tadashi, strokes him through it, pushes Tadashi right over the edge and he comes harder than he thinks he ever has.

            He’s breathing hard by the time the last few tingles are fading, limbs loose as Hiro looks down at him with wicked curiosity. Something sharp and hot twists in his belly and he gasps quietly when Hiro strokes him one last time. He’s so out of it that it takes him a minute to realize Hiro’s hard again.  

             And then he’s acutely aware of Hiro’s hardness against his thigh, of the erratic roll of Hiro’s hips as he goes for his second orgasm in so many minutes. Tadashi manages to unclench his hands from the sheets and grip Hiro’s hips carefully.

             He runs his thumbs along the juts of Hiro’s hipbones and watches the bliss on Hiro’s face as he comes against his thigh, all the while knowing that he is a _very_ bad man and should probably be sent to jail.

            “Told you I wanted to.” Hiro says smugly, voice breathy and exhausted as he slumps against Tadashi’s chest.

            “You sure did.” He replies mildly as Hiro spreads out over his chest and almost immediately falls asleep. He knows he’s gonna regret it in the morning, dried come is a pain to get out, but he just shifts him so Hiro’s knees are digging into anything delicate and wraps his arms around Hiro’s slender shoulders.

             He should feel worse about what he just did, he knows it, but the only thing he feels as he falls asleep is his little brother’s steady heartbeat and the warmth of Hiro’s breath on his collarbone.

**Author's Note:**

> edited by me, so please me know if you catch any errors. I'm a very lazy editor and probably missed a bunch of things.


End file.
